Method for deodorizing animal waste and preparing pet litter

ABSTRACT

A litter material, and the method of manufacture thereof, for deodorizing and absorbing the excreta from animals, and particularly, pet animals. The litter contains a mixture of dried citrus pulp bits and fines of specified sizes which coat the animal feces and absorb urine, respectively. The residual acids and sugars left in the dried pulp serve to neutralize the odor of the excreta.

This application is a division of my co-pending U.S. patent applicationSer. No. 471,660, filed Mar. 3, 1983, entitled "Citrus Pulp Litter ForPet Animals", now U.S. Pat. No. 4,424,763, which was acontinuation-in-part of my U.S. patent application Ser. No. 376,584filed May 10, 1982, now U.S. Pat. No. 4,386,580.

BACKGROUND OF THE INVENTION

The present invention relates to a new litter for coating, absorbing,and deodorizing animal wastes, and more particularly the excreta frompets, such as cats, and the method of manufacture thereof. The litter ismade from a mixture of dried citrus pulp bits of specified sizes.

Pet animals are extremely popular in present day homes, resulting in aneed for dealing with animal wastes. Such wastes must be dealt with in ahygienic manner, and preferably in a manner which will also prevent thespread of obnoxious odors throughout the household.

In the past, deodorizer material for pet animals has consisted of inertabsorbent particulate material for absorbing animal waste, particularlyurine, optionally with odor masking agents and the like. Among suchmaterials which have been used are vermiculite, saw dust, kaolin, groundwood pulp and the like. Other matetials, such as molasses serum, asdisclosed in U.S. Pat. No. 3,821,346 and cherry pits, disclosed in U.S.Pat. No. 3,816,577, have also been used for pet litters. Further, U.S.Pat. No. 2,179,591 discloses the use of sugar cane pulp as a poultrylitter and animal bedding material. U.S. Pat. No. 2,597,457 disclosesthe use of straw, wood fibers, or peat moss for use as a poultry littermaterial.

Other attempts to solve the problem of animal waste disposal haveutilized cages having an absorbent liner with an odor masking materialtherein. Such deodorizing materials function effectively for relativelyshort periods of time, however, they require frequent changing in orderto prevent the emission of objectionable odors from the animal cages.Such devices can also be rather expensive, particularly where absorbentmats and the like are concerned. This high expense detracts from theacceptance of such devices in the marketplace.

Numerous efforts have been made in the art toward discovering moreefficient alternatives to the known deodorizing materials. In view ofthe intended use of such materials for pets and the like, the art haslong recognized that any such materials must be produced from relativelycheap starting materials in order that the products can be marketed at acost consistent with those presently utilized.

It would therefore be advantageous to have an inexpensive material, i.e.litter, which serves to deodorize animal excreta, and in particular tohave such a litter which is adapted for use by cats and like animals.Such a litter should be capable of dealing with both feces and urine,and should utilize readily available raw materials. It would be afurther advantage if the litter material used with such a process wouldeasily coat an animal's feces and absorb the animal's urine.

The present invention relates to such a litter.

SUMMARY OF THE INVENTION

In accordance with the present invention, animal waste is deodorized byhaving the waste deposited in contact with dried citrus pulp containingbits and fines of specified sizes. The dried citrus pulp is obtainableby squeezing raw citrus fruit to remove the juice therefrom, cutting thesqueezed citrus fruit into small pieces of citrus pulp, drying thecitrus pulp, and chopping the dried pulp into bits, which are of a sizeto coat and adhere to the animal's feces. Alternatively, the pulp may bechopped into bits prior to drying or the bulk material after cutting anddrying is sifted through a series of screens to remove a largeproportion of the pulp particles above the required bit size necessaryto coat and adhere to the animal's feces, and which are digable by theanimal. Fines, or particles of even smaller size than the bits, are alsoretained naturally in admixture with the bits and serve to absorb theanimal's urine.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to deodorizing animal waste by having thewaste deposited in contact with dried citrus pulp containing bits andfine particles of specified sizes.

Citrus pulp comprises the skin, the cells adhered to the interior of theskin, the seeds, and the stems of citrus fruit such as oranges,grapefruits, and lemons. In any given quantity of citrus pulp, it is notunusual that a small amount of extraneous matter will be mixedtherewithin. For purposes of the present invention, citrus pulp can beconsidered to be whatever material is left over after the useablejuices, sugars, and liquors have been extracted from citrus fruit.

The citrus pulp used in the present invention is dried after all of theuseable materials (e.g. juice, sugars, liquors) have been removed fromthe fruit. The pulp may be dried in a large tumbler drier, similar to aconventional clothes dryer but on a much larger scale. For example, adryer used to dry citrus pulp may be fired by gas or oil, which heatsair that is blown into a drum on the order of 60 feet long by 20 feet indiameter. The citrus pulp is tumbled within the drum, with the hot airblowing over the pulp. Such dried citrus pulp has a deodorizing qualityand because it is dry, will readily absorb liquids brought into contacttherewith.

It has been found that when such citrus pulp is placed into contact withanimal excreta, the dried pulp absorbs moisture from the excreta,adheres to animal feces, and deodorizes both urine and feces.

The ability of the dried citrus pulp to adhere to the animal feces isparticularly important, in that the feces can be completely coated withthe dried citrus pulp thereby deodorizing the feces in an efficientmanner. This aspect is of particular importance when the method of thepresent invention is used to deodorize the excreta from cats. Cats areknown to dig in a litter material, after they have excreted, to cover upthe excrement. When dried citrus pulp is used as a litter for cats, thedeodorizing ability thereof is enhanced due to the adherence of thedried pulp to the excrement.

Dried citrus pulp for use in connection with the present method can beprepared by first washing citrus fruits, and then squeezing the fruit ina conventional squeezing machine. The juice extracted from the fruit inthe squeezing process can be used for human consumption in a variety ofproducts. Usable oils are also extracted from the fruits during thesqueezing process. In a preferred embodiment, lime or dolomiticlimestone is then added to the squeezed citrus fruit. The purpose of thelime or dolomitic limestone is to remove the soft, moist, slipperycoating which would otherwise remain on the squeezed fruit as a resultof the squeezing process. Thus, the lime or dolomitic limestone servesto facilitate the further processing of the squeezed fruit by automatedmachinery.

The squeezed fruit is then cut into small pieces of citrus pulp. Thecutting can be accomplised in a conventional hammer mill. It is notedthat the cutting step could occur before the squeezing step, however itis more economical to perform the squeezing step first.

The fruit can then be pressed a second time to extract additional sugarsand liquors which are of value in other products, for example tomanufacture a citrus molasses. The citrus pulp is then dried by anyconventional means, e.g., in a tumbler dryer as described above, andseparated, e.g. by sifting the mixture through a screen or series ofscreens, from extraneous granular particles and powder which typicallyare co-mingled with the dried citrus pulp. These granular particles andpowders are known in the trade as "fines".

After the citrus pulp has been dried and separated from the fines, it ischopped into smaller pieces, or "bits" for use as a litter material. Thechopping may be done in any conventional manner, for example by use of aconventional grinding or chipping machine. Alternatively, the pulp maybe chopped into bits and separated prior to drying.

The size of the chopped bits is important in determining the suitabilityof the dried citrus pulp as a litter material. The size of the bits mustbe such as to allow the bits to adhere to an animal's feces in order tocoat the feces. The dried citrus pulp bits are not pliable and thereforeif they are too large in size, they will not be capable of sufficientlycoating the animal's feces. On the other side of the scale, the driedcitrus pulp bits must not be so small that they will be in powder form,such that they could become airborne. It is preferable, however, thatsome fines be present because it has been found that they are valuablein admixture with the bits to absorb the animal's urine. Furthermore,the bits must be small enough that they don't look like citrus fruitskin, but large enough that they are digable by the animal using them,e.g. a cat.

In satisfying the above-mentioned criteria, it has been found that thecitrus pulp bits should be somewhere in the range of from approximately1/8 inch to 3/8 inch on each side thereof. The optimal size would besomewhere around 1/4 inch square. Sufficient fines of less than 1/8 inchon each side thereof should be present in admixture with the bits in anapproximate ratio of 90/80 to 10/20 of bits to fines by weight; theoptimum ratio being about 85:15.

The desired particle size may also be obtained by processing the citruspulp in a conventional manner, i.e.; squeezing and extracting the sugarsand liquors therefrom, cutting the squeezed fruit into small pieces anddrying it, and then sifting the dried and cut pulp through a screen orseries of screens to remove or "strain out" larger bits of 3/8 inch andgreater, leaving the bits of 3/8 inch and smaller and fines which occurnaturally in limited quantities, without resorting to secondary grindingor chopping.

The size of the citrus bits and fines in the litter materialmanufactured using the methods described above was analyzed to confirmthe particle size and ratio of the mixture obtained. A representative 10pound sample was sifted through a series of measured screens as follows:

Screen 1, #8--0.028, wherein there are eight openings per lineal inchand whose wire diameter is 0.028 inch. This screen will permit thepassage of particles 0.097 inch or smaller.

Screen 2, #14--0.020, wherein there are fourteen openings per linealinch and whose wire diameter is 0.020 inch. This screen will permit thepassage of particles of 0.051 inch or smaller.

Screen 3, #30--0.011, wherein there are thirty openings per lineal inchand whose wire diameter is 0.011 inch. This screen will permit thepassage of particles of 0.022 inch or smaller.

The weights and percentages of the graded sample was found to be asfollows:

1. 133.7 ounces or 83.5% was too large to fit through the first screen#8--0.028. This major portion of the sample ranged in size from 1/8 to3/8 inch. A small undetermined amount was between 0.125 and 0.098inches. For all practical purposes the major portion of the sample inthe 1/8 to 3/8 inch category.

2. 15 ounces or 9.4% was sifted through the first screen #8--0.028(whose hole size was 0.097 inch) but would not pass through the nextscreen whose hole size was 0.051.

3. 7 ounces or 4.4% was sifted through the second screen (whose holesize was 0.051 inch) but would not pass through the next size screenwhose hole size was 0.022; and

4. 4.3 ounces or 2.7% was sifted through the third screen whose holesize was 0.022 inch.

Summarizing, from the 10 pound (160 oz.) sample 83.5% was chip size pulp1/8 to 3/8 inch square and 16.5% was "fines" (small particles 1/10 inchor smaller) necessary in the absorption of urine. The sizes of the chipand granular portion (fines) were as follows:

133.7 oz. or 83.5%=3/8 to 1/8 inch

15 oz. or 9.4%=0.097 to 0.052 inch

7 oz. or 4.4%=0.051 to 0.023 inch

4.3 oz. or 2.7%=0.022 inches or less

Chips 1/8 to 3/8 inch=83.5% by weight

Fines 0.097 inch and smaller=16.5% by weight

The use of the dried citrus pulp, as set forth herein, in contact withanimal waste has been found to be an extremely effective for absorbingand deodorizing the pet waste. The pulp can be placed in a box so that apet, such as a cat, can be trained to return thereto whenever it has tourinate and/or defecate. The pulp can also be prepackaged in boxes ortrays for sale to a pet owner, said boxes or trays being suitable foruse by the pet immediately upon opening.

The present litter is useful for deodorizing the waste of many differentanimals, including cats, dogs, hamsters, gerbils, rats and other likedomesticated pets or animals. Likewise, the deodorizer is suitable fordomesticated birds or other pets such as reptiles. Of course, theinvention is also useful in zoos and other applications. Thus, thedescription contained herein is considered in all respects to beillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription.

I claim:
 1. A method for deodorizing animal waste comprising the stepsof:depositing said waste into contact with dried citrus pulp, said driedcitrus pulp being obtainable by: (a) squeezing raw citrus fruits toremove the juice therefrom; and (b) cutting and drying squeezed citrusfruit into small pieces of citrus pulp having a range of about 1/8 inchto 3/8 inch in both length and width.
 2. The method of claim 1 whereinsaid cut and dried pieces of pulp of between 1/8 and 3/8 inch in lengthand width constitute 80%-90% by weight of the bulk of said pulp.
 3. Theprocess for preparing a pet litter comprising:squeezing citrus fruit toremove the juice therefrom; and cutting and drying the squeezed citrusfruit into small pieces of citrus pulp between 1/8 to 3/8 inch in bothlength and width.
 4. The process of claim 3 wherein said cut and driedpieces of pulp between 1/8 to 3/8 inch in length and width constitute80%-90% by weight of the bulk of said pulp.
 5. The process of claim 3further comprising the step of adding lime or dolomitic limestone tosaid squeezed citrus fruit before it is cut, said lime or dolomiticlimestone serving to facilitate the further processing of said fruitduring said cutting step.
 6. The process of claim 3 wherein said fruitis grapefruit.
 7. The process of claim 3 wherein said fruit is orange.8. The process for preparing pet litter comprising:(a) squeezing rawcitrus fruit to remove the juices therefrom; (b) cutting and drying saidcitrus fruit; and (c) sifting said fruit to remove a proportion of saidpulp larger in size than between 1/8 to 3/8 inch in both length andwidth, which size has been determined as optimum to coat animal feces tobe deposited in said pet litter.